Tube socket



July 10, 1962 A. c. GREGSON 3,044,038

TUBE SOCKET Filed April 13, 1960 INV EN TOR. AL 4/0 0 C. Gecsso v3,044,038 eiterated July 10, 1982 nice 3,944,938 TUBE SGCKET Alvero C.Gregson, Garden City, N.Y., assignor to Instruments For Industry, Inc.,Hicksville, N.Y., a corporation of New York Filed Apr. 13, 1980, Ser.No. 22,052 2 Claims. (Cl. 339-91) This invention relates to sockets forultra-high frequency tubes and the like and more particularly to socketsfor tubes having coaxial longitudinal displaced electrode terminals.

Many different types of tubes designed especially for use in ultra-highfrequency circuits are provided with one or more electrodes in the formof radially extending circular flanges. In addition, it is not uncommonto provide other electrode terminals for such tubes in the form ofcoaxial, longitudinally displaced cylinders so that the tubes areespecially suited for use with coaxial transmission line circuitelements However, the characteristics of these so-called coaxial tubesthat permit their use at very high frequencies also make them desirablefor use in other types of circuits that do not employ coaxialtransmission lines. In particular, the low inter-electrode capacitanceand high transconductance common to such tubes make them very useful ingrounded grid circuits employing so-called lumped constants.

Sockets that are formed in such a way as to permit coaxial tubes to beused in lumped constant circuits encounter four problems. In the firstplace they must provide adequate electrical contact to the variouselectrodes to minimize the impedance encountered by electrical currentin reaching and leaving the electrodes. In the second place the socketstructure must be suificiently rugged to stand the use to which it willbe put. Normally this requires that the socket withstand severemechanical shocks'in order to be suitable for use in military equipment,even though the socket may also be used in nonmilitary equipment.Thirdly, the socket must permit easy insertion and removal of the tubeitself. And, finally, the socket must be so constructed as not tomitigate the desirable features of the tube by introducing highinterelectrode capacitances or lead inductances, which would reduce oraltogether remove the advantage to be obtained from using tubes havinglow electrode capacitance and low lead inductance.

It is a principal object of the present invention to provide a socketmeeting the foregoing criteria.

The means by which this and other objects are realized will be describedin greater detail in connection with the drawing in which:

FIG. 1 shows a cross-sectional view of a front elevation of a socketconstructed according to the invention;

FIG. 2 shows a perspective View in section, of the socket in FIG. 1; and

FIG. 3 is a perspective view of the tube mounting plate of the'socketshown in FIGS. 1 and 2.

the various tube terminals other than the one held by the plate.

Referring to FIG. 1, a type 6442 tube is indicated, generally, bythereference character 11. This tube comprises an anode 12 having heatdissipating flanges 13, the flanges 13 being removable and not part ofthe tube 11; a control grid terminal 14 in the form of aradially-extending flange; a tubular cathode contact terminal 16 coaxialwith the anode 12 and the grid 14; and two heater terminals 17 and 18,which are also concentric, or coaxial, with the other terminals of thetube. The heater terminal 18 is covered by a removable jacket to makebetter contact with the heater terminal, the jacket not being part ofthe tube. The base plate of the socket is indicated by the referencecharacter 19, and this plate is provided with an aperture 21. Aconductive ring 22 is attached to one side of the plate 19 surroundingthe aperture 21 to provide spacer means for properly locating a ring 23composed of resilient, conductive material, such as goldflashedberyllium-copper, and formed with inwardly extending contact fingers. Anannular ring 24 holds the ring 23 in place against the spacer 22 andfurther acts as a shield closely surrounding the reduced diameterportion 26 of the grid terminal 14 to prevent electro-rnagnetic couplingbetween the anode terminal 12 and the cathode 16 On the other side ofthe plate 19 is a cover plate '27 attached by means of a hinge 23 to thesurface of the plate 19. The cover plate 27 is preferably bifurcated andits extremities are provided with snap-fastening fingers 29 which extendthrough a pair of lower apertures 30 in the plate 19. The fingers 29interlock with rolled-over edges 31 of the apertures 36 to'hold thecover 'plate firmly in place against one surface of the grid flange 14.

The base plate 19' of the socket is supported on a conductive plate 32and is positioned in a slotted, or channelled, guide, the side membersof which are indicated by reference characters 33 and 34 and the basemember of which is indicated by reference character 36, which if desiredcan be made as one integral U-shaped member. A spring contact member 37may be aflixed to the plate 9 to lOCi over the member 36, which isaffixed to the plate 32, in order to insure good electrical contacttherewith. v

An insulating support 38 carries a folded-over, resilient, serratedconnector 39 in position to bear firmly against the anode terminal 12.in order to make proper electrical connection therewith. The serratedmember 3S is carried in a slot in the upper side of the support 38 inorder to assure that the member 39 will always be positioned in exactlya certain location with respect to the plate 19. The purpose of this isto insure that the main circuit constants will remain substantiallyidentically the same each time the tube 11 is removed and a new tube isinserted, for only in this way can an ultrahigh frequency circuitemploying lumped-constant ele- Basically, the socket of the inventioncomprises a plate having a hole through which one end of the tube isinserted. The hole is large enough for the body of the tube, adjacent toone tube flange, to extend through it, and resilient spring contactfingers are attached on one side of the plate surrounding and extendingpartly over the hole to make connection with the flange and to preventthe tube from passing entirely through the hole in one direction. Acover plate is attached, at least partly by snap fastening means, to theother side of the main plate to hold the flange of the tube firmly inplace against the resilient contact fingers. In addition, resilientcontact members, supported by insulators, are spaced adjacent to thelocation of the main plate so as to connect with conductive straps,since they serve ments be properly set up.

A similar insulating support 41 carries three upright members 4244 whichin turn support and fixedly locate three resilient contact members46-48. The contact members 47 and 48 may be in the form of simpleresilient only to carry low frequency or direct current to the'heaterterminals 17 and 18 and are not required to carry high frequencycurrent. The other contact member 46 is of the serrated type to makegood high frequency contact with the cathode terminal 16 of the tube.

FIG. 2 shows a perspective view of the socket of FIG. 1 illustrating thearrangement of the insulating members 38 and 41 togetherwith the contactmembers 39 and 4648 held by them. The contact members 39 and 46 i themolded plastic mount.

ment of the tube therefore cannot cause any shift of The inductance ofthe contacts 47 and 48 is not as much a matter of concern, and so theselatter contacts have only one tab, each, which is not shown in thiscross-sec:

tional view. The insulating members may be affixed to' the base plate 32in any convenient way, such as' by rivets, one of which is indicated byreference character 52.

The ends of the two side members 33 and 34 of the slotted guide in whichthe base plate 19 is supported are attached to upwardly directedextensions 53 of the base plate 36. The members :33 and 34 are at rightangles to the base member 36 to make it easy to insert the base plate 19therein. Thus, in order to change the tube it is merely necessary topull the baseplate 19 out of the guide, open up thehinged cover plate27, which allows the tube to be removed freely, place a newtube in theaperture 21, close the cover plate 27 and slip the base plate 19 backinto the guide formed by the members 33 and 34. The members. 33 and 34,or at least one of them, are resiliently biased toward each other tosqueeze the edge of the plate 19 tightly and to make good electricalcontact therewith. I I

FIG. 3 shows the plate 19 alone. The cover plate 27 is swung up out ofthe way to permit a tube to be inserted.

One corner of the plate 19 is shown broken away to reveal the serratedresilient clip 37. This clip is held in place by several rivets 54 nearthe bottom of the plate.

. The top of the plate 19 is bent over, asindicated by referencecharacter 56, to form a handle for pulling the plate out from betweenthe guide members 33 and 34.

.What has been described is a tube socket which is rugged and reliableand permits removal and replacement of the tube with positiveseatingassured each time. The socket permits quick replacement of tubeswithout disturbing any of the associated circuitry. This is accomplishedby the use of spring contacts which are directly connected to thecircuit and maintain their position in The removal and replacecircuitelements, which is extremely important in ultrahigh frequencyapplications.

It is to be understood that only one embodiment of the invention hasbeen described and that changes and modifications may be made theretowithout departing from the invention.

What is claimed is:

l. A socket for an electron discharge device having at least oneelectrode terminal in the form of an outwardly extending metal flange,said socket comprising: a metal member having an aperture therein; aspring contact member attached to said metal member adjacent to andoverlapping said aperture to bear firmly against one side of saidflange; a resilient snap-fastening member attached to the opposite sideof said plate and overlapping said flange to hold said electrondischarge device in operative position against said spring contactmember; and a U-shaped holder for said metal member, said U-shapedholder comprising a pair of resilient slide channels to hold theopposite edges of said metal member in firm contact.

2. The socket of claim 1 comprising, in addition, in-

i sulating members spaced from said U-shaped holder; and

a plurality of resilient electrode terminal connectors supported by saidinsulating members in longitudinally spaced relationship to makeconnection. with correspondingly longitudinally spaced electrodeterminals of said electron discharge device.

CTl

References Cited in the tile of this patent UNITED STATES PATENTS1,989,823 Raabe Feb. 5, 1935 2,372,987 Shaver Apr. 3, 1945 2,490,037Deiss et a1. Dec. 6, 1949 2,665,330 Wong Jan. 5, 1954 2,760,177 Holliset a1. Aug. 21, 1956 2,761,116 Dijkgraaf Aug. 28, 1956 Powell July 16,1957 OTHER REFERENCES Werner, C. P.: Electronic Equipment, February 1957(pages 18-21).

